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Nov. 30 92".

H. F. SMITH METHOD AND MPARATUS FOR PURIFYING GAS Filed Sept. 30. 192.13 SheetS-Sheei E 'EFE.

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Nov@ s@ me., l www@ H. F. bMlTH METHOD AND APPARATUS FR PURIFYING GASFiled Sept. 50, 1923 3 Sheets-Sheet 5 y fsf FWN iff-2755555 l En/22227?lli) Patented Nov., k3U, i126.,

HARRY F. SMITH, GE' DAYTON, CHO, ASSIG-NDR T0 THE GAS RESEARCH COMPANY,OF

DAYTON, Oi, A C'ORPORATIQN OF OHIO.

METHGID AND APPARATUS FOR PBFYING GAS.

AApplication filed September 30, 1921. Serial No. 504,269.

This invention relates to gas generation, and more particularly to animproved method of removing impurities from gas. and to apparatus forcarrying thatfmethod into effect.

One of the principal objects of the invention is to provide an improvedmethod of removing impurities from gas, such a gas, for example, asproducer gas, and apparatus for carrying that method into eect.

Other objects and advantages of the invention will be apparent from thedescription thereof set out below when taken in connection with theaccompanying drawing.

ln the drawing, in which like characters of reference designate likeparts throughout the several views thereof, p i

` g. l is a vien'v of a complete gas generatng system', comprisingpurifying apparaus embodying this invention;

2 is a sectional vievv, showing a slightly modified vform of purifyingapparatus, along the line 2-2 of Fig. 3;

Fig. 3 a plan vievv of this modified form of apparatus;

Fig. 4, is a detail view of one element of the. purifier shown in Figs.2 and 3;

Fig. 5 is a sectional view of another modilhed form of purifier; f

Fig. 6 is a sectional view of still another form of apparatus;

Fig. 7 is a detail vieuv of one element of the modification shown in G;

8 is a sectional vievv of another modi- (ic' L'on of thc purifier; and

ig. 9 is a detail vien7 of still another forni of construction.

rlhis agpncatio'n is a continuation, in part, of the application ofHarry F. Smith Serial filed ein 24. E2G. And Fig.

.l the is a cuplicate of the drawcopending application. p* applicationdiscloses purii constructec accordance hah his invention. and the methodof effecting the cleaning of gas through the tilir/.ation of thatpurifying apparatus, the

ying apparatus forming merely one nt of the complete system disclosedtherein. Vfhile the invention forming` the subject matter of thisapplication is of general applicatiomit is thought 'that a clearerAderstanding of the invention will be cured through aY description of itconnection With the same type ofy gas generating system as forms thesubject matter of the original application.

As shown in Fig. l, the purifier is associated With a gas generator,Which consists of a metallic shell l0, housing an upper Zone or fuelreservoir 11, and a lower zone or generating chamber l2.' The upper endof the shell is closed by meansof a suitable top 13, so positioned as toprovide a Water pan or trough lll from Which moisture is supplied-to thegenerating chamber during operation of the producer. The top 13 is alsoprovided vvith an'upstanding flange surrounding an opening 16 throughwhich fuel is introduced into' the reservoin a cover 17, having adepending flange 1S adapted to extend down into the Water Within thecrough 14 to effect a seal, being provided for clos-` ing this openingduring operation of the producer. The lower zone, that housing thegenerating chamber l2, is provided with suitable lining, this liningpreferably consisting of a layer of l'irebrick 30, of small heatingcapacity, backed by a layer of heat insulating material 33. The lovverend of the producer is closed, and the lining thereof is suitablysupported by means of a plate 20, held in place by any desired means,the means shoivn being preferable, since it minimizes conductivity ofheat from the plate into'the producer shell. An ash pit- 34 connectedwith the generating chamber l2, is provided, a removable grate 'beingpositioned Within the ash pit to support the fuel bed Within thegenerating chamber. A depending flange l5 is provided vvithinthe upperzone of the producer, this flange being spaced from the shell 10, andserving as a fuel reservoir. An inverted trough like member ll,cooperating With the. pan or trough 14 serves as a vaporizer, receivingheat from the generating chamber, or the generatedgas, to vaporize someof the vwater Within the trough, this vapor passing through the pipe l()to the ash' pit 34e, whence it is taken up by the ingoingy blast of airand carried' into the generating Zone. The producer thus operativelydescribed is the same as that described in the copending applicationabove referred to. A producer of this type is not essential inconnection with the invention formingthe subject matter of thisaarticular a plication im1 urit f the surface coating.

Ill)

purity carried by the gas is comparatively small and a layer of finelypulverized material Will function satisfactorily for a con siderableperiod of time. As impurities, particularly tar, are deposited upon thepurifying material, however, it tends to form a gunnny and imperviouslayer thereon which increases the resistance to the flow of gas throughthe purifying mate-rial and tends to render it ineffective as aseparator. It therefore becomes necessary to either place a new supplyof material Within the purifier orto so treat the material alreadytherein as to return it to its original leffectiveness. @ne method ofrestoring the effectiveness of this material, When it becomes i coatedWith tar, is to agitate it to break up 1n order to accomplish thisresult a ralreelilre member G5 is attached to the top 5'?, the teeth ofwhich extend into the layer of material. Rotation of the. top 57 to dragthev teeth of the ralre member through the material Will so agitate thatmaterial as to brealr it up to restore it to its original condition.Handles 66 are attacher to the top 57 to` facilitate rotation thereof.

Zhen the producer is operated on a fuel, such as bituminous coal, whichgenerates a gas rich in tar it is generally more satisfactory if thelayer of pulverized material be changed from time to time, Without anyattempt to restore its effectiveness by agitating it through operationofthe rake. Since the material Within the purifier is itselfcarbonaceous, it is found that, when large quantities of tar are being;separated from the gas, this material and the separated tar may bereadily briquet'ted and the resulting briquettes used in the producer asfuel. Thus Waste products which are present in connection with theoperation are utilized. Gf course, the rake 65 may bedispcnsed with, ifdesired, and new material added from time to time as needed to replacethe old material.

And if desired the filamentous or fabric member 62 may be made in theform of an endless belt, so that by advancing the belt fresh materialmay be moved into operative position and the used material moved into aposition Where it may be treated to restore its effectiveness, orbriquetted for subsequent use in the producer as fuel.

The purified ,gas passes off through the pipe 59 to any desired place ofuse or stoi age. As shown in the drawing the pipe 59 of any desiredcharacter, being insert-ed Within the pipe 71.

As stated above, impurities are `deposited upon the purifying,` mate"iai, during the cleaning operation, yforming a gummy layer upon theupper surface of the purifying; inaterial. This deposited layer consistsof a mixture of finely pulverized fuel, Which is introduced, to agreater or less extent, into the generatingchamber alone` with the fuelcharged thereto, admixed` with tar. lf this layer of deposited materialis removed, the original purifying material will be found unimpaired ineffectiveness. W here 'the ralre described above is utilized this layeris merely broken up, so that the original layer of purifying material isagain exposed. ln the form of apparatus shown 'in Figs. 2 and 3 thislayer of deposited `material is entirely removed, by being scraped offof the tcp of the original purifying material. And as often as such alayer forms, and a new layer will beformed each time ther producer isoperated, it may be removed to restore the effectiveness of thepurifier. ltis not necessary that this layer be removed after eachoperation of the purifier, however, for the producer ordinarilyoperates, several at least, before the increasedV resistance due to thedepositing of this material within the purifier seriously affects theoperation. i

As shown in Fig. 2 the. purifier comprises a metallic pan 90, having atop 91 therefor the top and pan being held in position by means ofspring clamps 92. The top is provided With a groove Within Whichsuitable packing material 93 is inserted to malte a tight joint andprevent leakage. The gas to be cleaned passes into the shell throng: ithe pipe 45, and out through the pipe.

Attached to the end of the outlet pipe 59, Within the purifier shell, isa fitting 94, the upper end of Which is cone shaped. Located Within thepurifier is a pan 95, the bottom of Which has au opening' thereinsurround ed by an upstanding flaiige 96, which is conicalin shape tocooperate with the conical member 94. TWhen the device is in assernbledposition the panfafj is supported upon the outlet pipe 59', the conicalshaped inem-- ber 9s extending into the opening,v surround ed by theflange 96, the construction being such that the resulting` ioint'is gastight. ositioned Within the pan is an inverted cup shaped member 97, thefree edge of which seats upon the bottom of the nan and is rigidlyattached thereto. preferably in ,aus tight connection, the atta unent inthe construction shown being; for'v Weldingthe two parts together.r inglegs 98 are also provided, these le ing' Welded at opposite ends to thepan and the member 97. This member 9.7 has a plurality/.tof holes orperi'orations therein, a screen, 1,00, of wire mesh being; positionedover these holes and held inplace by suitable means, such as solderingor spot welding. A layer of fabric .101, such for instance as theflannel described above, is positioned on top of the screen 100 thisfabric being .held in position by the spring band 102. This spring maybe of any desired construction, such as the type of coil spring` whichis ordinarily used for closing screen doors. The specific constructionof this spring' is therefore not shown. The upstanding wall 109 of themember 95, and the l, depending wall -1 of the member 97 are spaced asubstantial distance apart, the depth of the member 95 ,being greater.than the depth of the member 97. The pan 95,

during operation, contains a finely divided or pulverized purifyingmaterial, 60', this material forming a layer of substantially uniformthickness over the member 97, and filling the trough between the flange103 and the depending` flange 104.

entire surface of the layer 60', the top of the purifier' is providedAwith a series of baffle i'lates. .its shown, particularly in Fig. 3,there are three of these plates. The plates Y 110 and 111 arepositioned. a short distance in front of the inlet opening', to whichthe pipe 45 is connected, and substantially transverse to the directionof flow of the incomingg'as. These plates are spaced apart asu'liici'ent distance to allow most of the incoming gas to pass freelybetween their ends, but to strip off the outer layers of the gas andcause the gas thus separated to eddy or circulate within the 4spacelocated between these baffle plates and the wall of the purifier. Thethird battle plate 112 is arranged substantially parallel to the twosmaller baille plates and is correspondingly positioned uponl theopposite side of the purifier housing. The gas which passes between thebaffles 110 and 111 contacts with this plate 112 and is caused tocirculate within the space between `the two sets of baffles. Some of thegas passes beneath the plate 112 into the space between that plate andthe wall of the purilior. l fill of the battle plates are so arrangedthat they are at all times above the surface of the *layerl of purifyingmaterial. This construction is such that the gas, containing theimpurities is caused to pass through the layer of purifyingmaterial insuch wise that it deposits lthese impurities over the surface of thelayer 60 in a substantially uniform layer. 1 y

Each time the producer is operated therefore, a layer consisting offinely divided fuel 'al 117, being provided.

admired with tar, and the like, is deposited. As the number ofV depositsincreases the resistance to flow through the purifier correspondinglyincreases, and this resistance will ymetallic member 113 having woodenplates 1111 attached thereto, which carry teeth 115, of the characterdescribed `above in connection with Fig. 1. The end'of the metallicmember is extended and positioned within a slot in the operating shaft116, a suitable set screw holding,` the two in assembled position.through the top 91, a support-ing and packing` means indicated generallyby the numer- The outer end of the shaft is constructed to r ceive asuitable operating handle or tool,not shown, whereby it may be rotatedtocause the scraper member to correspondingly rotate to both` break upthe surface of the layer of purify-` ing material and at the same timeremove any excess material.

Where this type of'purifier is used the fuel introduced into thegeneratinlg'V chamberl of the producer is not as carefullyscrcened, toremove finely divided fuel as is the case in the type of purifierillustrated in Fig. 1. ln fact substantial quantities of finelydividedrmaterial may be purposely introduced into the generating,`chamber along with the fuel, so that the layer of 'material depositedupon the main body of the 'purifying material, the layer 60', willcontain, proportionately, considerable quantities of vsolid fuel.V Theresulting` layer will then be less sticky and gummy than is the casewhen 'the finely divided fuel is more carefully screened out before thefuel is introduced into the 'generating chamber. And these layers maybemore easily removed, therf-ifore.l f Y 'It is sometimes found that,during,` operation of the apparatus the layer of purifying material willsettle or pack so that thel scraper member 'will not function to removeall of the material deposited thereon. In such case as this, the teethon the scraper member are especially beneficial. Of course the teeth maybe dispensed with if desired.

In Fig. 5 is shown amod-ilied form of cleaning' apparatus. Thiscomprises `a inetallic shell or pan 125, havinga top 126 therefor, iwhich top is provided with a groove 1727, adapted lto receive the upperseV The shaft 116 extends outwardly 'l edge of the shell or pan 125,suitable packing material 128 being inserted within said groove to maltea tight joint and prevent leakage of gas or air therethrough. Positionedwithin the bottom of the shell or pan 125 is a supporting,` ring 129,preferably welded to the bottom of the` member 125, the upper edge ofthis ring having a ground surface to receive a correspondingly groundsurface on the lower face of the grid member 130, which serves tosupport the purifying material. rlhis grid, preferably, consists of acylindrical sleeve, one end of which is open, the other end beingprovided with a plurality of cross bars 131, to which is soldered orspot welded a screen member 132. This preferably consists of a layer ofMonel metal filter cloth, although it may be of conventional wire mesh,or may be perforated plates of the character described above inconnection with Fig. 1. This screen may be attached to the grid member130 in any other desirable or suitable way, but attaching it by spotwelding; constitutes one of the easiest and most effective ways ofsecuring` it. Supported upon the screen 132 is a layer of filamentousmaterial 133, such asflannel or other cloth, which is held in place andproperly stretched by means of the spring 134C, which is of the typedescribed above in connection with Fig. 2 and is snapped into the groove135, thus holding' the cloth 133 properly positioned and stretched, atthe same time allowing` ready removal thereof. Purifying material, ofthe character described above is supported upon this cloth.

Especially where the purifier is used in connection with a producerfurnishing gas to an internal combustion engine, particun larlv whenthat engine is closely connected to the purifier, it is found thatpulsations or vibrations occur as a result of the operation of theengine, which tend to agitato the purifying' material causing it to drawaway the shell of the purifier. ln purifier such as disclosed in Fig. 1thi sometimes causes trouble. For if the puri ying/(material draws awayfrom the shell a sufficient distance it will permit the passage of gas iough the purifier without that l.fijas being forced to pass through thelayer of purifying4 material-` Therefore the cleaning effectiveness ofthe device will be impaired. ln order to take care of this condition thepurifier shown in 5 has the. supporting grid 130 spaced from thesliell'l25, this space being; filled with purifying' material. Eventhough the purifying material tends to draw ay from the shell,therefore, the gas will, nevertheless, still pass through the layer ofpurifying material. Preferably the ring 129 is also spaced from theshell of the purifier, this space being filled with a materialV calinform but is more in the nature of a pan.

concrete may be dispensed with and purifying material used to fill thisspace.

'lhe is introduced into the purifier', above the layer of purify ingmaterial,` through the pipe 45', and passes out from the purifier, frombelow the purifying niaterial, through the pipe 59. A drain 136,provided with a removable plus' 137 is provided in the bottom of thepurifier for draining ofi any moisture and impurities that 7 may collecttherein. The tcp 126 is provided with a handle 138 for easy manipulationtl'iereof. ln order to facilitate removal of the grid, for purposes ofcleaning', it provided with a plurality of lugs or hooks 13?) adapted toreceive a suitable tool or hook for lifting' this grid from thepurifier.

In Figs. 6 and 7 is shown still another form of purifier, in whichgridsv 15G are substituted for the perforated screens or plates 61, ofthe modification shown in Fig. 1. These grids may be of any desiredshape, so long as the effective opening through them is quite large topernfiit the free passage of gas, but the form of grid shown functionssatisfactorily. lf desired one of these grids may be provided with pins151, constructed to cooperate with corresponding holes, not shown, inthe other grid, to properly position them relative to each other.interposed between the two grids, and sustained by them, are two layersof wire screen, 152- or other perforated materia between which is posi;tioned a layer 153 of filamentous material, such as flannel, of thecharacter described above. The two grids, with the screens and layer ofcloth between them, are held firmly togetherl by means of the member154, which as shown, consists of a bolt passingthrougrh a centrallyarranged opening in each of the grids, the end of the bolt beingthreaded within the opening' in the lower grid. The head of the bolt isadapted to contact with the upper grid, so that when the bolt istightened the two grids with the screen and layer of cloth l etween themare tightly fas tened together. The layer of filtering ma terial issupported upon the unitary structure thus described. rf "his particularsti ture is advantageous in that it facilitates newal of the layer offiltering material, and facilitates removal of the grids, and Vociatedscreen and cloth. Because of the coustruction the grids, etc., with thepari'V material thereon, may be lifted bodily the shell or pini of thepurifier.

ln Fig', 3 is shown still ano-"f purifying apparatus. above describedthe purifier shell. cyl

` iso in that it has sul tantially ,Circa 1er di: eter thanV hei-eht.The modification shown 8 is also cylindrical, but the shell 2W hassuliistantially greater height than diameter. rlhis shell has a top Ztltherefor,

which as in the modification described above, is provided with a groove202 for receiving the upper end of the shell, suitable packing material203 being inserted within thev groove to make a tight joint. The gas tobe cleaned passes into the shell through the pipe 45, and passes outthrough the pipe 59. As in the constructions above, the layer offiltering material is interposed between the inlet and the outlet pipes.But in this kparticular modification the construction is such as tofacilitate and make particularly easy the renewal of the filteringmaterial. rl'he inner end of the outlet pipe is conical sl'iaped, asshown at 204, this conical shaped end being constructed to cooperatewith a correspondingly shaped opening 205 in the base of the member 200.Supported upon the member 206 is a member 207 which is perforated andwhich corresponds in func tion with the lower perforated plate G1, ofthe modification shown in Fig. 1; that is it yserves to ksupport thefiltering material.

The member 206 has a clamping flange 208 cooperating therewith whichserves to clamp to that member a hollow member 210 which is of a shapecorresponding .to the member 207, being spaced a suitable ydistancetherefrom and if desired open at its upper end, its lower end being alsoopen and firmly held between the member 200 and the flange 208. Themember 210 is preferably made of wire mesh or screen, the size ofopenings therein therein, as shown in Fig. 9 so that the gas rllhememmay readily pass therethrough. ber 20'? Vhas cooperating therewith alayer or lstocking of filamentous material 211, which, as in themodifications above, is preferably of wool or flannel. 206, 207 and210are so proportioned that a space of suitable dimensions, is providedbetween them to receive the purifying material which is of the samecharacter as that described above.

By means of the construction described Vrenewal of the purifyingmaterial is rendered a very simple matter. In order to renew thismaterial the top 201 is removed, and the members 206, 207 and 210,which, for purposes of convenience in description are designated as acartridge for receiving the purifying material, are removed as a unit.rllhis cartridge being removed is in- IThe membersl verted, and thefouled purifying material dumped therefrom after which it is filled withnew material and replaced in the purifier shell. rllhe conical shapedend 20a of the outlet pipe and the hole 205 have their cooperatingsurfaces finished to form a ground joint so that leakage therethrough isprevented. In replacing the charged cartridge it is inserted into thepurier and positioned with the conical mennier 204 within thecooperating hole 205, thus supporting it.

A baffle plate 2.15 is attached to the top 201 and when in position isinterposed between the purifier cartridge and the gas inlet. Theincoming gases, especially where the purifier is located quite closelyto the gas generator, may be very hot and the baffle not only pre ventsdirect iinpingement of these gases on the cartridge and inclosedpurifying material, but causes these gases to travel around in contactwith the shell 210 and thus cools them. i

A bail or handle 210 is carried by the cartridge to facilitate itsren'iovalfroni, or insertion into, the shell 210.

With a purifier of the type shown in Fig. 8 it is not necessary that thepurifying 1na terial be renewedwhenever the cleaningefficiency fallsoff. lfn this type of apparatus the impurities tend to collect upon therouter surface of the member 210, from which they may be removedwhenever desirable. Brushes constructed for movement to sweep thesurface member 210 may be. provided. Or the starting blower, shown inFig. 1, may be reversed to cause a current of air to flow through thepurifier in a direction reverse to the `direction of flow of the gas toblow the layer of deposited impurity from the. surface of the member210. Another method Ofremoving the layer of impurity is to hold open theinlet valve of the engine so that an explosion impulse will act thereon. In practice it is found that very often therewill be an impulse ofthis character set up whenever the engine stops, which impulse issufficient to blow the layer of iinpurities free. Where this type ofimpulse occurs the efficiency of the purifier will beV automaticallyrestored ,at the end of each period of operation. Also, except whenthereis a large proportion of tar in the deposited impurities, there is amaximum thickness to which the deposit will build up. Any furthermaterial deposited will drop ofi" thus maintaining a definite resistanceto flow and a definite cleaning effectiveness. But there. should be alayer of purifying material4` of lsufficient thickness to cause satis#factory cleaning, originally provided in the purifier, the depositedmaterial being merely added to this original layer. -While in thevarious types of purifiers, as set out above, the sizing ofthe purifyingmaterial may vary over a substantial range, itis generally lflf) foundthat most satisfactory operation will be .secured if this material is sosized that the particles of impurity to be removed from the gas areslightly smaller than the particles of the purifying` material.

l/Tfhile the method herein described, and the forms of apparatus forcarrying this method into effect, constitute preferred embodiments ofthe invention, it is to be understood that the invention is not limitedto this precise method and forms of apparatus, and that changes may bemade in either Without departing from the scope of the invention whichis defined in the appended claims.

`l/Vhat is claimed is:

1. rlhe method of removing from producer orthe like the-impurities whichnormally exist therein as discrete particles of solid and liquidcharacter, Which consists in first applyingl upon a sustainingfabric alayer of purifying material in which the -din'iensions of' the particlesof material are of the same order of magnitude as the particles ofmaterial being removed and then passing the impurity-laden pas through acontinuously maintained layer of such finely divided material supportedupon such sustaining` fabric.

2. Purifying apparatus of the character described for removing fromproducer gas or the like the impurities which normally en ist therein asdiscrete particles of solid and liquid character, Whichcomprises ahousing` having' an inlet for the impurity-laden*gas and an outlet forthe clean gas, a layer of fabric Within said housing and interposedbetween the said inlet and outlet, and a continuously maintained layerof finely divided material upon said fabric to constitute a purifyinglayer, said material being` composed of particles the dimensions ofwhich are of the same order of magnitude as the particles of impurity tobe removedv from the gas.

3. Purifying apparatus of the character described for removing' fromproducer gas' or the like the impurities Which normally exist therein asdiscrete particles of solid and liquid character, which comprises ahousing having an inlet for the impurityladen gas and an outlet for theclean gas.y a layer of fabric Within said housing` and interposedbetween said inlet and outlet, and a layer of finely divided materialapplied upon said fabric before the passage of a substantial quantity ofimpurity-laden gas to constitute a purifying layer, said material boincacomposed of particles the dimensions of which are of the same order ofmagnitude as the particles of impurity to be removed from the gas.

4l. Purifying apparatus of the character described for removing fromproducer gas or the like the impurities which normally exist therein asdiscrete particles of solid and liquid character.. which comprises ahousing having an inlet for thc impurityladen gas and an outlet for theclean a layer of fabric Within said housing` interposed between the saidinlet and outlet, a continuously maintained layer of finely dividedmaterial of substantiallyv uniform thickness upon said fabric toconstitute a purifying` layer, said material being composed of particlesthe dimensions of Whi h are of the same order of n'nfinitude as tnoparticles of impurity to be removed from the gas, and moans for removingfrom the surface of the layer of purifying` material the impuritiesdeposited thereon Without removing the normal layer of purifying`material.

5. Purifying apparatus, of the cl aractcr described, for removing` froma gas, such as producer gas, the impurities which einsttherein in theform of smoke, which impurities normally exist in 'the as discreteparticles; which comprises a housing,` having' an inlet for thein'ipurity laden gas, and an outlet for the purified 5 a perforatedpartition within sa d housing', and interposed between the said inletand outlet openings thereof the perforations Wit-hin said partitionbeing' sulliciently large to permit free passage of gas therethrough; alayer of finely divided carbonaceous material, upon said perforatedpartition, the dimensions of the par cles constituting this layer beingof the order of magnitude of the particles 0f impurity to be removedfrom the gas, and of considerably smaller size than the perforationsWithin the partition; and

a layer of fabric carried by said perforated diaphragm, and positionedto support the layer of finely divided carbonaceous material, theconstruction of the fabric being; such that free passage of the gastherethrough is permitted, but passage of the finely divided purifying'material is prevented.

6. Purifying apparatus, of the character described, comprising ahousing' having,` an inlet pipe opening; thereinto; anv outlet pipeextending into said housing` and terminating` in a conical supporting'member; a perforated partition, constructed to support a layer ofpurifying material, and a stpporting member therefor having` an opening;therein defined by a conical Wall construct@ ed to cooperate With theconical end of the outlet pipe, to support the said perforated partitionin assembled positionv with the perforated partition and layer ofpurifying,l material thereon intermediate the inlet and outlet openings.

'i'. A purifying apparatus comprising a housing having an inlet and anoutlet` whereby a fluid to be purified may he passed through saidhousing; a partition Within said housing, said partition consisting ofand lil@

two perforated metallic diaphragme having a layer of fabrictherebetween; and a layer of finely divided charcoal on said partition;

` the arrangement being such that all fluid il il through the purifyingmaterial; and a scraper' member positioned in scraping relation with thenormal surfacevof the layer of purifying material and provided with apluralityof agitating teeth, for breaking up and removing the layer ofdeposited impurity, to restore the purifying .material to its originaleffectiveness, without interrupting` the operation of the apparatus.

9. A purifying apparatus for removing impurities from a gas, such asproducer gas,

con'iprising a housing havingV an inlet and an outlet; a bed of finelydivided carbona* ceous material within said housing, interposed betweensaid inlet and said outlet,

. said bed of purifying material being adapted to remove impurities fromthe gas. passing therethrough andfto retain those impurities largelyupon the surface first presented to the gases, and a scraper memberprovided with agita-ting teeth, associated with said surface, forbreaking up and removing the layer of deposited impuritiesto restore thepurifying material to its original effectiveness without interruptingthe operation of the apparatus. 'i

10. A purifying apparatus, for removing 'inpurities from gas such asproducer gas, in which the impurity laden gas is passed throu h a la erof aurif ino' material consisting of finely divided carbonaceousvmaterial, which comprises a housing; an inlet pipe opening into saidhousing; an outlet pipe, extending.k into said housing, the end of saidpipe Within said housing terminating in a conical supporti-ng member; acartridge comprising spaced perforated cylindrical walls mounted upon abase member having an opening therein vdefined by a .conical fiangeconstructed to cooperate with the conical end of the outlet pipe, thecartridge being constructed to contain a layer of finely dividedpurifying material within the space between the spaced walls, so thatthe cartridge and purifying material therein may be inserted in, orremoved from, the housing as a unit, the construction .being such thatwhen in assembled position, gas passing Vinto the housing from the inletpipe, and out from the housingthrough the. outlet pipe, passes throughthe layer of purifying material within the cartridge.

ll. A purifying apparatus, for removing impurities from gas such asproducer gas, in which the yimpurity laden gas is passed through a layer`of purifying material, consisting of finely divided carbonaceousmaterial which comprises al housing; an inlet pipe opening into saidhousing; an outlet pipe, extending into said housing, the vend of saidpipe within .said housing terminating in a conical supporting member; yacartridge comprising spaced perforated walls mounted -upon va basemember having an Opening therein defined by a .conical flangeconstructed to cooperate with the conical end of the outlet pipe, thecartridge being constructed to contain va layer of finely di` videdpurifying material within the space between the spaced walls, .the.construction being such that when in assembled position, gas passinginto the housing from the inlet pipe, and out from the housingthroughthe outlet pipe., passes through Vthe layer of purifying material.within the cartridge; and means whereby the cartridge may be insertedinto or removed from the housing.

l2. The method, in the removing of im'- purities from a gas, suchas'producer gas, while such gas is passing from the generating chamberof the producer to a gas en`- gine, for vcausing operation of that gasengine; which consists in operating the engine to canse. passing ofthegas through a bed of finely divided purifying material, the impuritiesbeing removed `froi'nrthe gas and deposited upon the bed of purifyingmaterial, to .form a layer of impurities thereon which increasesresistance to flow of the Vgas through the bed of purifying .material tolower its cleaning effectiveness;

and, from time to time, subjectingthe layer of purifying material to an.explosion impulse, resulting fromcombustion of t-hegas ywithin theengine cylinder, to agitate the layer of deposited impurities, torestorethe cleaning effectiveness of the bed of purifying material. i'

13. The method, in the removalL of imA purities from a gas, such asproducer gas; which. consists in passing the gas through a maintainedbed of finely divided purifying material, the impurities rbeing removedfrom `the gas and deposited upon the bed of purifying material, to forma layer thereon which increase-s resistance to flow of the gas throughthe bed of purifying material to lower its cleaning effectiveness, thesurface of the bed of purifying material being arranged at an angle,with respect to the`horizontal, which is `greater than the angle ofrepose of the deposited impurities, sonthati liu! l Si) the depositedimpurities Will automatically drop olf, thus maintaining a substantiallyuniform resist-ance to flow of the gas through the purifying material.

14. A purifying apparatus for removing impurities from a gas, such asproducer gas, comprising a housing having an inlet and an outlet; aperforated member therein, a

`layer of fabric, such as flannel cloth, upon said perforated member, alayer of purifying material, consisting of finely divided carbonaceousmaterial upon the layer of fabric, and a second perforated membercooperating with the layer of purifying material, to retain thatpurifying material in place, the particles of purifying material beingslightly larger than the particles of impurity to be removed thereby,and the construction being such that the perforated member, the fabricmember and the layer of purifying material, When in assembled position,are located between the inlet and outlet openings of the housing.

l5. Purifying apparatus, of the character described, for removing from agas such as producer gas, the impurities which exist therein as smoke orfume, which impurities normally exist therein as discrete particles andin Which the impurity laden gas is passed through a layer of purifyingmaterial, consisting of finely divided carbonaceous material, whichcomprises a housing; an inlet pipe opening into said housing; an outletpipe extending into said housing, the end of said outlet pipe Withinsaid housing terminating in a conical supporting member; a base member,having an opening therein delined by a conical Wall constructed tocooperate with the conical end of the outlet pipe, to support the saidbase member, a perforated plate carried by said base member and adaptedto support a layer of finely divided purifying material, the particlesof said material being of considerably smaller size than theperforations in said plate, and a layer of filamentous material, such asflannel cloth, carried by said perforated plate, and adapted to directlysupport the purifying material, the said layer of filamentous materialbeing of such character as to permit the free passage of gastherethrough, but to prevent the passage of the finely divided purifyingmaterial, the construction being such that When in assembled positiongas passing into the housing through the inlet pipe, and ont from thehousing through the outlet pipe, Will pass through the layer ofpurifying material.

In testimony whereof I hereto affix my signature.

HARRY F. SMITH.

